Production and evaluation the experimental immunocastration vaccine produced in Shiraz Razi Vaccine and Serum Research Institute, in sheep

Gonadotropin-releasing hormone (GnRH) stimulates the pituitary gland to secrete sex hormones. In the present study, we compared dierent established anti-ertility conjugates o GnRH with whole GnRH I-KLH (produced in Razi Institute) in a male rat model and then the eect o GnRH I-KLH was evaluated in sheep compared with castrated ones and control. At irst, six-week-old male rats (n=30) were divided into 5 groups and 4 o them immunized intramuscularly and administered in weeks 1, 3, 5 and 7 and the other group was considered as control. Antibody production, hormone levels and testicular diameter changes were assessed, together with, sperm movement and eects on organ weights. Secondly, 15 rams were divided into 3 groups (immunized (whole GnRH I-KLH), castrated and control). Then the antibody production, hormone levels, body weight and sperm count were evaluated in all groups. Similar high levels o antibody secretion were observed in all the immunized groups (rats and sheep), although whole GnRHI- KLH produced a sustained level o production or an additional week. Similarly, testosterone levels were signiicantly (p0.05) reduced in all immunized groups (rat and sheep). There were no signiicant changes observed in body weight (rat and sheep) and testicular diameter o immunized rats compared with the untreated controls. However, in terms o sperm motility and sperm number in rats, the best anti-ertility eects were observed with lGnRH-III-TT and GnRH-I-KLH and to a lesser extent whole GnRH-I-KLH and we could not collect any live and normal sperm rom immunized sheep. inally, considering all the above-mentioned subjects in addition to availability and easier and cheaper way o preparation, we came to this conclusion that whole GnRH-IKLH satisactorily met most o our avorite criteria and could be used in immunocastration vaccine production purposes successully.